[wip] initial async generator support (#1560)

feat: initial async generator support

.babelrc

@@ -1,5 +1,8 @@
 {
-  "plugins": ["transform-es2015-modules-commonjs"],
+  "plugins": [
+    "transform-es2015-modules-commonjs",
+    "syntax-async-generators"
+  ],
   "env": {
     "test": {
       "plugins": ["istanbul"]

.eslintrc

@@ -5,6 +5,7 @@
     "mocha": true,
     "es6": true
   },
+  "parser": "babel-eslint",
   "parserOptions": {
     "ecmaVersion": 8,
     "sourceType": "module"

Makefile

@@ -7,7 +7,6 @@ export PATH := ./node_modules/.bin/:$(PATH):./bin/
 
 PACKAGE = asyncjs
 REQUIRE_NAME = async
-UGLIFY = uglifyjs
 XYZ = support/xyz.sh --repo git@github.com:caolan/async.git
 
 BUILDDIR = build
@@ -21,7 +20,7 @@ LINT_FILES := lib/ test/ $(shell find perf/ -maxdepth 2 -type f) $(shell find su
 
 UMD_BUNDLE := $(BUILDDIR)/dist/async.js
 UMD_BUNDLE_MIN := $(BUILDDIR)/dist/async.min.js
-UMD_BUNDLE_MAP := $(BUILDDIR)/dist/async.min.map
+# UMD_BUNDLE_MAP := $(BUILDDIR)/dist/async.min.map
 ALIAS_ES := $(addprefix build-es/, $(addsuffix .js, $(shell cat $(SCRIPTS)/aliases.txt | cut -d ' ' -f1)))
 ALIAS_CJS := $(patsubst build-es/%, build/%, $(ALIAS_ES))
 ES_MODULES := $(patsubst lib/%.js, build-es/%.js, $(JS_SRC)) $(ALIAS_ES)
@@ -81,26 +80,23 @@ $(UMD_BUNDLE): $(ES_MODULES) package.json
 	node $(SCRIPTS)/build/aggregate-bundle.js
 
 # Create the minified UMD versions and copy them to dist/ for bower
-build-dist: $(DIST) $(DIST)/async.js $(DIST)/async.min.js $(DIST)/async.min.map
+build-dist: $(DIST) $(DIST)/async.js $(DIST)/async.min.js # $(DIST)/async.min.map
 
 $(DIST):
 	mkdir -p $@
 
 $(UMD_BUNDLE_MIN): $(UMD_BUNDLE)
 	mkdir -p "$(@D)"
-	$(UGLIFY) $< --mangle --compress \
-		--source-map $(UMD_BUNDLE_MAP) \
-		--source-map-url async.min.map \
-		-o $@
+	babel-minify $< --mangle -o $@
 
 $(DIST)/async.js: $(UMD_BUNDLE)
 	cp $< $@
 
 $(DIST)/async.min.js: $(UMD_BUNDLE_MIN)
 	cp $< $@
 
-$(DIST)/async.min.map: $(UMD_BUNDLE_MIN)
-	cp $(UMD_BUNDLE_MAP) $@
+# $(DIST)/async.min.map: $(UMD_BUNDLE_MIN)
+# 	cp $(UMD_BUNDLE_MAP) $@
 
 build-es: $(ES_MODULES)
 

lib/applyEach.js

@@ -15,7 +15,7 @@ import map from './map';
  * @memberOf module:ControlFlow
  * @method
  * @category Control Flow
- * @param {Array|Iterable|Object} fns - A collection of {@link AsyncFunction}s
+ * @param {Array|Iterable|AsyncIterable|Object} fns - A collection of {@link AsyncFunction}s
  * to all call with the same arguments
  * @param {...*} [args] - any number of separate arguments to pass to the
  * function.

lib/applyEachSeries.js

@@ -10,7 +10,7 @@ import mapSeries from './mapSeries';
  * @method
  * @see [async.applyEach]{@link module:ControlFlow.applyEach}
  * @category Control Flow
- * @param {Array|Iterable|Object} fns - A collection of {@link AsyncFunction}s to all
+ * @param {Array|Iterable|AsyncIterable|Object} fns - A collection of {@link AsyncFunction}s to all
  * call with the same arguments
  * @param {...*} [args] - any number of separate arguments to pass to the
  * function.

lib/concat.js

@@ -12,7 +12,7 @@ import concatLimit from './concatLimit';
  * @memberOf module:Collections
  * @method
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`,
  * which should use an array as its result. Invoked with (item, callback).
  * @param {Function} [callback(err)] - A callback which is called after all the

lib/concatLimit.js

@@ -11,7 +11,7 @@ import mapLimit from './mapLimit';
  * @method
  * @see [async.concat]{@link module:Collections.concat}
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`,
  * which should use an array as its result. Invoked with (item, callback).

lib/concatSeries.js

@@ -10,7 +10,7 @@ import concatLimit from './concatLimit';
  * @method
  * @see [async.concat]{@link module:Collections.concat}
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`.
  * The iteratee should complete with an array an array of results.
  * Invoked with (item, callback).

lib/detect.js

@@ -17,7 +17,7 @@ import doParallel from './internal/doParallel';
  * @method
  * @alias find
  * @category Collections
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
  * The iteratee must complete with a boolean value as its result.
  * Invoked with (item, callback).

lib/detectLimit.js

@@ -12,7 +12,7 @@ import doParallelLimit from './internal/doParallelLimit';
  * @see [async.detect]{@link module:Collections.detect}
  * @alias findLimit
  * @category Collections
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
  * The iteratee must complete with a boolean value as its result.

lib/detectSeries.js

@@ -11,7 +11,7 @@ import doLimit from './internal/doLimit';
  * @see [async.detect]{@link module:Collections.detect}
  * @alias findSeries
  * @category Collections
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
  * The iteratee must complete with a boolean value as its result.
  * Invoked with (item, callback).

lib/each.js

@@ -18,7 +18,7 @@ import wrapAsync from './internal/wrapAsync'
  * @method
  * @alias forEach
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async function to apply to
  * each item in `coll`. Invoked with (item, callback).
  * The array index is not passed to the iteratee.

lib/eachLimit.js

@@ -12,7 +12,7 @@ import wrapAsync from './internal/wrapAsync';
  * @see [async.each]{@link module:Collections.each}
  * @alias forEachLimit
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - An async function to apply to each item in
  * `coll`.

lib/eachOf.js

@@ -49,7 +49,7 @@ var eachOfGeneric = doLimit(eachOfLimit, Infinity);
  * @alias forEachOf
  * @category Collection
  * @see [async.each]{@link module:Collections.each}
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - A function to apply to each
  * item in `coll`.
  * The `key` is the item's key, or index in the case of an array.

lib/eachOfLimit.js

@@ -12,7 +12,7 @@ import wrapAsync from './internal/wrapAsync';
  * @see [async.eachOf]{@link module:Collections.eachOf}
  * @alias forEachOfLimit
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - An async function to apply to each
  * item in `coll`. The `key` is the item's key, or index in the case of an

lib/eachOfSeries.js

@@ -11,7 +11,7 @@ import doLimit from './internal/doLimit';
  * @see [async.eachOf]{@link module:Collections.eachOf}
  * @alias forEachOfSeries
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async function to apply to each item in
  * `coll`.
  * Invoked with (item, key, callback).

lib/eachSeries.js

@@ -11,7 +11,7 @@ import doLimit from './internal/doLimit';
  * @see [async.each]{@link module:Collections.each}
  * @alias forEachSeries
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async function to apply to each
  * item in `coll`.
  * The array index is not passed to the iteratee.

lib/every.js

@@ -11,7 +11,7 @@ import doParallel from './internal/doParallel';
  * @method
  * @alias all
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async truth test to apply to each item
  * in the collection in parallel.
  * The iteratee must complete with a boolean result value.

lib/everyLimit.js

@@ -11,7 +11,7 @@ import doParallelLimit from './internal/doParallelLimit';
  * @see [async.every]{@link module:Collections.every}
  * @alias allLimit
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - An async truth test to apply to each item
  * in the collection in parallel.

lib/everySeries.js

@@ -11,7 +11,7 @@ import doLimit from './internal/doLimit';
  * @see [async.every]{@link module:Collections.every}
  * @alias allSeries
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async truth test to apply to each item
  * in the collection in series.
  * The iteratee must complete with a boolean result value.

lib/filter.js

@@ -12,7 +12,7 @@ import doParallel from './internal/doParallel';
  * @method
  * @alias select
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {Function} iteratee - A truth test to apply to each item in `coll`.
  * The `iteratee` is passed a `callback(err, truthValue)`, which must be called
  * with a boolean argument once it has completed. Invoked with (item, callback).

lib/filterLimit.js

@@ -12,7 +12,7 @@ import doParallelLimit from './internal/doParallelLimit';
  * @see [async.filter]{@link module:Collections.filter}
  * @alias selectLimit
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {Function} iteratee - A truth test to apply to each item in `coll`.
  * The `iteratee` is passed a `callback(err, truthValue)`, which must be called

lib/filterSeries.js

@@ -11,7 +11,7 @@ import doLimit from './internal/doLimit';
  * @see [async.filter]{@link module:Collections.filter}
  * @alias selectSeries
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {Function} iteratee - A truth test to apply to each item in `coll`.
  * The `iteratee` is passed a `callback(err, truthValue)`, which must be called
  * with a boolean argument once it has completed. Invoked with (item, callback).

lib/groupBy.js

@@ -17,7 +17,7 @@ import groupByLimit from './groupByLimit';
  * @memberOf module:Collections
  * @method
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async function to apply to each item in
  * `coll`.
  * The iteratee should complete with a `key` to group the value under.

lib/groupByLimit.js

@@ -10,7 +10,7 @@ import wrapAsync from './internal/wrapAsync';
  * @method
  * @see [async.groupBy]{@link module:Collections.groupBy}
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - An async function to apply to each item in
  * `coll`.

lib/groupBySeries.js

@@ -10,7 +10,7 @@ import groupByLimit from './groupByLimit';
  * @method
  * @see [async.groupBy]{@link module:Collections.groupBy}
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {number} limit - The maximum number of async operations at a time.
  * @param {AsyncFunction} iteratee - An async function to apply to each item in
  * `coll`.

lib/internal/asyncEachOfLimit.js

@@ -0,0 +1,63 @@
+import breakLoop from './breakLoop';
+
+// for async generators
+export default function asyncEachOfLimit(generator, limit, iteratee, callback) {
+    let done = false
+    let canceled = false
+    let awaiting = false
+    let running = 0
+    let idx = 0
+
+    function replenish() {
+        //console.log('replenish')
+        if (running >= limit || awaiting || done) return
+        //console.log('replenish awaiting')
+        awaiting = true
+        generator.next().then(({value, done: iterDone}) => {
+            //console.log('got value', value)
+            if (canceled || done) return
+            awaiting = false
+            if (iterDone) {
+                done = true;
+                if (running <= 0) {
+                    //console.log('done nextCb')
+                    callback(null)
+                }
+                return;
+            }
+            running++
+            iteratee(value, idx, iterateeCallback)
+            idx++
+            replenish()
+        }).catch(handleError)
+    }
+
+    function iterateeCallback(err, result) {
+        //console.log('iterateeCallback')
+        running -= 1;
+        if (canceled) return
+        if (err) return handleError(err)
+
+        if (err === false) {
+            done = true;
+            canceled = true;
+            return
+        }
+
+        if (result === breakLoop || (done && running <= 0)) {
+            done = true;
+            //console.log('done iterCb')
+            return callback(null);
+        }
+        replenish()
+    }
+
+    function handleError(err) {
+        if (canceled) return
+        awaiting = false
+        done = true
+        callback(err)
+    }
+
+    replenish()
+}

lib/internal/breakLoop.js

@@ -1,3 +1,4 @@
 // A temporary value used to identify if the loop should be broken.
 // See #1064, #1293
-export default {};
+const breakLoop = {};
+export default breakLoop;

lib/internal/eachOfLimit.js

@@ -3,6 +3,8 @@ import once from './once';
 
 import iterator from './iterator';
 import onlyOnce from './onlyOnce';
+import {isAsyncGenerator, isAsyncIterable} from './wrapAsync'
+import asyncEachOfLimit from './asyncEachOfLimit'
 
 import breakLoop from './breakLoop';
 
@@ -15,6 +17,12 @@ export default (limit) => {
         if (!obj) {
             return callback(null);
         }
+        if (isAsyncGenerator(obj)) {
+            return asyncEachOfLimit(obj, limit, iteratee, callback)
+        }
+        if (isAsyncIterable(obj)) {
+            return asyncEachOfLimit(obj[Symbol.asyncIterator](), limit, iteratee, callback)
+        }
         var nextElem = iterator(obj);
         var done = false;
         var canceled = false;

lib/internal/wrapAsync.js

@@ -4,10 +4,18 @@ function isAsync(fn) {
     return fn[Symbol.toStringTag] === 'AsyncFunction';
 }
 
+function isAsyncGenerator(fn) {
+    return fn[Symbol.toStringTag] === 'AsyncGenerator';
+}
+
+function isAsyncIterable(obj) {
+    return typeof obj[Symbol.asyncIterator] === 'function';
+}
+
 function wrapAsync(asyncFn) {
     return isAsync(asyncFn) ? asyncify(asyncFn) : asyncFn;
 }
 
 export default wrapAsync;
 
-export { isAsync };
+export { isAsync, isAsyncGenerator, isAsyncIterable };

lib/map.js

@@ -23,7 +23,7 @@ import map from './internal/map';
  * @memberOf module:Collections
  * @method
  * @category Collection
- * @param {Array|Iterable|Object} coll - A collection to iterate over.
+ * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
  * @param {AsyncFunction} iteratee - An async function to apply to each item in
  * `coll`.
  * The iteratee should complete with the transformed item.